This invention relates to hyperbranched polymers having different types of reactive functional groups and methods of preparing hyperbranched polymers having different reactive functional groups.
Hyperbranched polymers are tree-like macromolecules that possess more extensive chain branching than traditional branched polymers containing mostly primary and secondary branches attached primarily to linear main-chain backbones, but less extensive and regular than perfectly branched dendrimers. In other words, hyperbranched polymers have a molecular architecture that is intermediate between traditional branched polymers and ideally branched dendrimers.
While several different types of dendrimers containing different reactive functional groups have been prepared by various synthetic strategies, no such counterparts have been reported for hyperbranched polymers. A notable exception to this is hyperbranched macromolecules that result from ABx polymerization and that ideally contain a single A group in the focal point, if cyclization is suppressed. However, this single functional group per hyperbranched polymer molecule may not be available for further reaction due to such factors as steric hindrance and intramolecular cyclization, and the single functional group is normally present at a negligible concentration such that it generally does not have any utility. Therefore, hyperbranched polymers having a plurality of different functional groups per molecule, and particularly two different functional groups that are reactive under different conditions, are presently unknown.
This invention pertains to hyperbranched polymers having a plurality of each of at least two different types of functional groups.
In one aspect of the invention, the two different functional groups are reactive under different conditions. In other words, a first type of functional group is reactive and a second type of functional group is not reactive under a first set of conditions, and the first type of functional group is not reactive and the second type of functional group is reactive under a second set of conditions. This allows the first type of functional group to be used for one purpose, such as for cross-linking the hyperbranched polymer molecules to form a network structure, and the second type of functional group for another purpose, such as to form a nanoscopic domain which can act as a particle-like reinforcing agent within the hyperbranched polymer network. In addition to this, the second type of functional group can also be used for attachment of a variety of species, such as molecules of drugs, markers, sensors, catalysts, etc.
Other aspects of the invention relate to cross-linked polymer networks containing hyperbranched domains having a plurality of each of at least one type of functional groups: cross-linked polymer networks containing a nanoscopic inorganic reinforcing agent covalently bonded to the polymer network, hyperbranched polymers containing nanoscopic inorganic particles distributed in and covalently bonded to the hyperbranched polymer, methods of synthesizing hyperbranched polymers having a plurality of each of at least two different types of functional groups, methods of forming cross-linked polymer networks from hyperbranched polymers having a plurality of each of at least two different types of functional groups, methods of preparing cross-linked polymer networks containing a nanoscopic reinforcing agent covalently bonded to the polymer network, and methods of preparing hyperbranched polymers containing nanoscopic inorganic particles distributed in and covalently bonded to the hyperbranched polymer.
These and other features, advantages and objects of the present invention will be further understood and appreciated by those skilled in the art by reference to the following specification and claims.